The rising epidemic of type 2 diabetes is a major cause of disability and death. With an estimated cost of $245 billion in 2012, diabetes also represents a significant burden to the U.S. health care system. Following the successful trial of the Diabetes Prevention Program (DPP) in 2002, the translation of this lifestyle intervention to community settings has been a major public health focus, with significant support from the CDC through the National Diabetes Prevention Program (NDPP). Although the NDPP has been shown to be effective for enrolled participants, resulting in weight loss of 5-7%, independent of setting and population group, there are striking disparities in engagement. Participation rates for men are particularly low (often <30% of a class);participation rates for Black and Latino men are even lower (<20%). Men generally have poorer health outcomes and lower life expectancies than women. Men of color, who are more likely than their white counterparts to face significant disadvantage, experience higher rates of diabetes-related complications, such as cardiovascular disease and end-stage renal disease. Given the disproportionate burden of diabetes and its complications for disadvantaged groups, targeted diabetes prevention programming is a crucial component of public health planning. This proposal is for a translational, cluster randomized trial of the NDPP in 16 sites for the main study, tailored to recruit, engage and retain men from disadvantaged communities in type 2 diabetes prevention. The proposed tailored program, the NDPPB, will first be pilot tested with 30 men in 2 sites before being implemented in 8 NYC Parks and Recreation Department (REC) sites in disadvantaged communities in each of the 5 boroughs of NYC, with 8 standard NDPP REC sites for comparison. Working in collaboration with a stakeholder Advisory Panel of community leaders and academic experts, we will conduct focused outreach to the target population. We will implement the evidence-based NDPP curriculum, with tailoring to promote increased engagement of men. For our proposal, "engagement" encompasses recruitment, group participation, and retention. We propose having male-only coaches and groups members, adaptations to the dietary messaging, and increased emphasis on physical activity. For comparison, the standard mixed-gender groups will be implemented at eight separate REC sites, matched by NYC borough, using the standard NDPP curriculum. In the main study, we will enroll a total of 830 participants (age 18 and older) across the 16 REC sites.
The specific aims of the proposed study are: 1) to assess the effectiveness of the NDPPB with respect to reductions in BMI (primary outcome) compared to the standard NDPP model. We hypothesize that men engaged in the NDPPB will have reductions in BMI at 16 weeks at least equivalent to those in the standard NDPP;2) to examine the extent to which recruitment/enrollment, intervention and retention strategies tailored for men at risk for type 2 diabetes in disadvantaged communities are associated with improved engagement of the target population (secondary outcomes). We hypothesize that implementation of the NDPPB will proceed with more rapid recruitment and enrollment of men than in the standard NDPP;3) to identify demographic, psychosocial, neighborhood, and REC site characteristics associated with differential recruitment and intervention effects;and 4) to provide estimates of incremental costs of the NDPPB in comparison to the standard community-based NDPP programs and relative to the primary outcome of change in BMI. Strengths of our proposal include: rigorous design and analytic methodologies, with randomization by site, a participatory approach and an adaptive process for development of our intervention with the NYC REC sites, along with a strong community and expert Advisory Panel. If our hypotheses are supported, this study will inform real-world implementation of the NDPP program in community settings for high-risk men and make a significant contribution to reducing the diabetes burden in these populations.

Public Health Relevance

The public health relevance of this proposal is that although the National Diabetes Prevention Program (NDPP) has been shown to be effective in preventing or delaying type 2 diabetes for enrolled participants, there are disparities in enrollment and engagement by men, especially those from disadvantaged communities. If our hypotheses are supported, this study with its recruitment strategies and adapted curriculum will inform real- world implementation of the NDPP program in accessible community settings for men and will make a significant contribution to reducing the diabetes burden in these high-risk populations.